In recent years, opportunities for making presentations of plans, proposals, estimates, etc., are increasing. For example, during sales activities, when visiting a customer, the sales discussions are made by explaining the product while displaying the documents in the display of a personal computer, and negotiating with the customer while displaying the different estimates that have been prepared. However, if several estimates are displayed simultaneously in the display, it becomes difficult to view them, but if they are displayed successively, it becomes difficult to compare the displayed estimate with the ones displayed previously. In addition, in a meeting, quite often the plans and proposals are displayed on a screen using a projector, and the presentation is made by distributing in advance to the members of the meeting paper documents corresponding to the screen displays. In this case, if there is any additional report or a sudden urgent topic to be discussed, it becomes necessary to prepare paper documents related to the additional report or urgent topic in the middle of the meeting, which disturbs the progress of the meeting.
In view of this, in order to carry out presentation smoothly without any obstruction to the meeting or sales discussion, it is possible to constitute the display screen using a reflection type liquid crystal display device having a memory effect as disclosed in Japanese Laid-Open Patent Publication No. 2004-117406, and distributing it to the customers or members of the meeting instead of paper documents.
However, although the display apparatus described in Japanese Laid-Open Patent Publication No. 2004-117406 has high power saving effect and is provided with good visibility, since it is provided with an operation panel that the user operates, a slot for inserting recording media, and a power supply, the customers or the members of the meeting will have to listen to the explanation while operating the display apparatus, it is not user-friendly.
Therefore, it is possible to think of a method in which the customers or the members of the meeting do not operate the display apparatus but the person making the presentation operates it using a host machine, thereby displaying images in the display apparatuses of the customers or of the members of the meeting. In particular, in such a case, it is necessary to display the images simultaneously in a plurality of display apparatuses, and a display system that is efficient and offers ease of use to the customers or the members of a meeting is desired.